assigmok



Dec. 11,1923. 1,476,828

G. MONRATH ANNEALING MAsTIc PIPE Filed July 22 1919 Snom/1110i eusrav Monahan, or unvv nona, n. r., assienon, er nasa-in Assmann-iure, no annuale aannam ravine coureur, or rninannnriara, animierter-inra, a een1 ANNJEMNG MASTC PIPE Application tiled July 252, lilla. Serial No. lltlft.

To all avlium, it 'may concern Be it lrnovvn that l, GUS/rnv Monna'rir, residing at New York city, in the county of New orlr, State ol New York, have invented certain new and useful lmprovements in annealing li/lastic Pipes; and ll do hereby declare the following to be a lull, clear, and enact description olf' the invention, such as will enable others skilled in the art to which it appertains to make, and use the same.

'lhis invention relates to the manufacture el asphalt mastic pipes, conduits, retainers, and the like, and has for its object the provision ot certain improvements in the method et manufacturing such articles.

Asphalt mastic pipes, conduits, retainers, and the like are commonly made by pouring the mastic composition, heated to a suiliciently high temperature to secure the olesired duidity lor casting, into an appropriate mold, and allowing the mastic composition to hardenl or set in the mold, Whereupon the cast article is removed or separated from the mold in any convenient manner. ldlollow cylindrical articles may be satisfactorily cast in a three-part mold having a semi-cylindrical base or bottom member to which are hinged, or otherwise suitably attached, covers or top members in the torni ot sector-shaped quadrants. Yllhe covers are spaced apart at their upper edges and are provided With vertical flanges 'or Walls forming a trough along the entire length oi the mold into which the Huid ma-` terial is poured. The cast article thus has an integral longitudinal rib or foot formed by the mastic material inthe trough of the mold.

ln the manufacture of, asphalt mastic ipes, conduits, and the like, ,in molds of the oregoing type, I have found it to be of im-y portance to control the contraction and cooling of the asphalt mastic material after it has been poured into the mold, so as to prevent an uneven cooling oi of the rib or foot of the pipe exposed to the air. The cooling off .of the exposed rib of the casting causes the cooled ortion to become hard and inflexible an thereby prevents the natural contraction of the mastic material. with the attendant formation of a compact mass, thus causing the finished casting to be spongy or permeated with minute blisters and consequently liable to leak. I

While also specially retarding the cooling and solidication or hardening et the upper portion ot the casting. 'This allows the maf terial in the bottom of the mold to cool tiret and, during the contraction oli the material, enables the still tluid material in the upper part oi the mold to replenish the material in the lower portions thereof. ln this the casting cools slowly or gradually from the bottom up, and the natural contraction ot the casting as it cools isloflset or com pensated lor the overlying body of still `duid material in the upper part ci the mold.

The coolin olf the rib or loot ot the cast-1 ing may, it esired, be further impeded or delayed by appropriate means. Ill`hus, "i have round it ot advantage, in certain cases,

to cover the open trough ol the mold vvith a bar of iron heated to a temperature di' from 300 F. to 400 l?. 'llhis heated bar of iron is large enough to cover the open trough of the mold, and is placed in position alter the mold has been filled with the duid' mastic material, whereupon the mold is covered with the inverted asbestos lined trough here` inbefore described.

ln the manufacture ot cast asphalt mastic articles in general, l have found that a uniform slow cooling or annealing ot the casting is of especial advantage in the pro- .duction of a compact and homo eneous product. To this end, ll have toun it satisfactory to provide annealing boxes of insulating material, such, for example, as Wood with an asbestos lining. I have alsoused with advantage plain Wood boxes buriedrin the ground flush with their tops and cov# ered with a ti ht fitting lid. The filled molds are place in these annealin boxes or vaults immediately after the pouring of the fluid mastic material, and are allowed to tdi . with asphalt mastic composition cooling in integrally asa part of the pipp an annealin vault in the ground.

The mol represented in the accompanying drawings ma be made of rolled iron or other appropriate material. The lower half of the mold is a semi-c lindricai member 6 vto which are hinge the quadrant shaped upper members 7. The members 7 terminate at their tops in ianges 8 spaced apart and extending upwardly to provide therebetween an opening offfor example, three to five inches in width, depending upon the size of the ipe to be cast. This opening between the anges 8 provides an open trough at the top of the mold into which the hot fluid material may be poured, and at the same time enables a rib or foot to be formed The mold is provided wit end plates 9 which permit the core 10 to. be inserted and removed and accurately centered and supported thereby and which will also permit ready removal of the finished casting. The core 10 is preferably of the collapsible type so as to facilitate its removal'from the hardened casting.

The asphalt mastic composition, heated to a suiiiciently high temperature to secure the desired iluidity for casting, is poured into the substantially horizontal mold through the open trough at the top thereof. The mold is then covered with an inverted heat insulating trough, as indicated in Fig. 2 of the drawings. This trough, as shown in the drawings, comprises a wooden member 11 lined with a heavy layer of asbestos 12.

. The trough l1--12 extends well down over the sides of the mold and maintains-the mastic material in the up er part of the' mold in a fluid condition unti the mastic material in the lower part ofthe mold has set or hardened. As previously explained, a source of heat maybe applied above the open trou h of the mold for assisting in maintaining t e mastic material in the upperpart of the mold in a iiuid condition until after the setting of the material in the lower portion of the mold. Thus, in Fig. 2 of the drawingpnl 1c 1s have illustrated a bar of iron 13 wh heated to a temperature of from 300 F. to

400 F. and placed over the open trough of,

the mold, whereupon the mold is covered with the inverted insulating trough 11-12.

In Fig. 3 of the drawings, there is represented an annealin vault buried in the ground with its top ush with the surface o I` the ground. The vault, as shown in this iig-- ure, is composed of an outer wooden box li provided with an asbestos lining 15. As previously mentioned, the asbestos lining l5 may be omitted when the annealing box is buried in the ground, and where the annealing box is rovided with a 'thick asbestos lining, it wiliDgenerally bennnecessary to bury it in the ground, in order to secure satisfactory cooling of the casting. The mold is filled with the fluid mastic material in the usual manner and immediately placed in the annealing "vault, and the vault is then closed with a tight fitting cover 16 which may also have an asbestos lining 17. The mold is kept in the annealing box until the casting has completely cooled off, and is then removed from the box andthe casting taken out of the mold. y

Froml the foregoing description, lit will be observed that the invention contemplates a slow and gradual cooling of the asphalt mastic casting, under thermal conditions,

ermitting natural contraction of the casting and the formation of a compact homogeneous product. Furthermore, the casting is cooled under such conditions as to prevent the premature settin of a portion thereof and the conse uent ormation of im rfections as a'resu t of the contraction o subsc- .quently settin portions ofy the casting. An

annealing of t e casting is thus' roduced as a result of the slow and gre ual cooling thereof, and a more compact and homogeneous product can be thereby obtained than by any heretofore customary method of casting asphalt mastic articles with which I am acquainted.

In the modification of the invention illustrated in Fig. 2 ofthe drawings, the inverted trough 11-12 acts as a heat retaining member,`and may be of any desired shape and size.- Preferably, it conforms more or less closely in configuration to the contour ofthe mold, so as to prevent the entrance of cold air into the space between the mold and the shield or trough, with the attendant ob'ectionable chilling effect upon the material in the mold.

I claim:

1. The improvement in the casing of articles from molten asphalt mastic which comprises slowly cooling the casting, under thermal conditions permitting natural contraction thereof, so as to assure the formation of a compact hontigeneous product; substantiallyms descri 2. The improvement in the casting in molds of articles from molten asphalt mastic which comprises graduali coohng the casting, while 1n the mold, un er conditions .pre-

will

venting the premature setting of a portion of the casting, so as to obviate formation of imperfections as the result thereof; substantially as described.

3. The improvement in the casting in.

molds of asphalt mastic pipe which comprises slowly and gradually cooling the casting as a whole in thenmold, so as to permit which comprises slowly and gra-dually cool-` ing the casting as a Wholewhile specially retarding the cooling of its upper portion, so as to permit contraction of .the casting into a compact, homogeneous mass.

5. 'lhe improvement in the horizontal casting in molds ol' asphalt mastic pipe which comprises slowly and gradually cool ing the casting as a whole in the substantially horizontal mold while specially retarding the coolingof its upper portion.

6. 'lhe improvement in 'the casting of articles from molten asphalt mastic in a mold having an open' trough at the top thereof which comprises slowly cooling the'casting while in the mold from the bottom up and thereby maintaining the material in the/upper portion of the mold in a fluid condition until the material in the bottom of the mold has set; substantially as described.

7. The improvement in the casting of articles from molten asphalt mastic in a mold having an open trough at the top thereof which comprises 'causing the casting to set in the mold from the bottom up and replenishing the material of the mold' during its contraction b the overlying body of the still fluid material in the upper portion of the mold; substantially as described.

8. The improvement in the casting in molds of articles from molten asphalt mastic which comprises insulating the upper por-l -tion of the mold to cause the casting to set in the mold from the tially as described.

- 9. The improvement in the casting oit articles from molten asphalt mastic in a mold having an open trough at thetop thereof which comprises applying a source of heat above the open trough of the mold for maintaining the material in the upper portion of the mold iny a fluid condition until the mabottom up substanin the lower portion terial in the bottom of the mold has set;

substantially as described.

10. rlhe improvement in the casting of articles from molten asphalt mastic in a mold having an upper trough at the top thereof, which comprises applying a source of heat above the open trough of the mold and insulating the upper portion of the mold to cause the casting to set in the mold from the bottom up and to maintain the material in the upper portion of the mold in a fluid condition until the material in the bottom of the mold has set; substantially as described.

ln testimony whereof ll aiix my signature.

GUSTAV MONRATH. 

